Motor compressor unit for refrigerating apparatus



Nov. '1, 1938. R. M. GETCHELL ET AL 2,134,936 MOTOR COMPRESSOR UNIT FOR REFRIGERATING APPARATUS Original Filed Oct. 30, 1928 4 Sheets-Sheet l Nov. 1,1938. R. M. GETCHELL ET AL I 2,134,935

MOTOR COMPRESSOR UNIT FOR REFRIGERATING APPARATUS Original Filed Oct. 50, 1928 '4 Shets-Sheet a Nov. 1, 1938. 1 R. M. GETCHELL ET AL 2,134,936

MOTOR COMPRESSOR UNIT FOR REFRIGERATING APPARATUS Original Filed Oct. 30, 1928 4 Sheets-Sheet 5 III" A Nov. 1, 1938. 'R. M. G ETCHELL E41 AL 2,134,936

RESSOR UNIT FOR REFRIGERATING APPARAT/US Original Filed det. so, 1928 4 Sheets-Sheet 4 Patented Nov. 1, :1

MOTOR COMPRESSOR UNIT Fon' REFRIG- EltATlNG APPARATUS Robert M. Getchell and Ralph K. Miller, Dayton,

Ohio, assign'prs, by mesne assignments, to Gen- 1 eral Motors {Qorporation, a corporation of Delaware Application October 30, 1928, Serial No. 315,988

. RenewedFebruary 274, 1937 I .6 Claims. (01. 230-139) This invention relates to refrigerating apparatus and. more particularly to a mechanical refrigerating system provided with a refrigerant liquefying unit having a rotary refrigerant compressor with'a lubricant circulating means.

An object of this invention is to provide a refrigerating system with a refrigerant pump having a lubricant pump drivingly connected to said refrigerant pump, in order to insure positive flow of lubricant as well as of refrigerant.

Another object of this invention is to provide.

a refrigerant liquefying unit with a rotary pump and with a positive lubricant circulating means provided with a cooling coil for the lubricant. Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompany- Fig.3 is a diagrammatic view of a refrigerating system embodying features of this'invention.

Fig. 4 is a vertical cross sectional view taken along the line 44 of Fig. 2.

Fig. 5 is a vertical cross sectional view taken along the line 5-5 of Fig. 2.

Fig. 6 isa vertical crosssectional view of a modifiedform of refrigerant pump, taken along the line 6-6 of Fig. 7, with the vanes shown in elevation.

Fig. 'l is a cross sectional view taken transversely to Fig. 6. Fig. 8 is a cross sectional view taken along the line 88 of Fig. '7.

Fig. 9 is an elevation of one of the end plates of the pump shown in Figs. 6, '7, and 8. a

A refrigerating apparatus embodying features of this invention may include a refrigerant liquefying unit generally designated'as 20 and a refrigerant evaporating unit generally designated 1 as 2|. The refrigerantliquefled in the unit 20 g is conveyed, for instance. by a pipe 22, to the refrigerant evaporating unit 2| and is returned bythe pipe 23. The pipe 22 may d liver the refrigerant through a fitting 24 whic includes a float valve control mechanism, not shown. The pipe 23 may receive the refrigerant from the unit 2| thru the fitting 25. The unit 2| may be of any desired type, for instance of the type described in the patent to R. G. Osborn 1,556,708 patented October 13, 1925. The refrigerant liquefying unit may be operated by an electric motor 26 which may be connected to the source of electricity 21. The motor may be controlled in its starting and 6 stopping operation by means of a snap switch 28 which maybe operated by an expansible bellows 29 connected to the pipe 23. v

The refrigerant liquefying unit may comprise a refrigerant pump 30 which discharges com- 10.

pressed or high side refrigerant thru the check.

valve 3| into a lubricant and refrigerant reservoir 32. The reservoir 32 may be connected to a 'condenser .33, which may include a double spiral coil of finned pipe either in series or in parallel. condenser 33 may discharge the condensed refrigerant into a circular refrigerant receiver 35. The receiver35 may be connected to the pipe 22 in order to deliver liquid refrigerant to said pipe. The pipe 23 may be connected to the intake 36 of 20 the refrigerant pump. The pump 30 may be drivenby means of a shaft 40 which may pass throughthe motor 26 and may terminate at its connection with a fan 4|. The shaft 40 may be provided with a shoulder 42 which forms a diaphragm type of seal with the bellows 43, which is hermetically attached'as by a gasket 43a to a plate 44 whichforms part of the pump casing. The seal prevents the passage of refrigerant out past the shaft 40. 30

The shaft 40 is provided with an excentric offset 45 which is adapted tocause the pumping member 46 to move in a circular orbit. A slidingly pivoted key 41 may be connected to the pumping member 46.. The key 41 may be slidingly con- 35 nected to the cylindrical key-way member 48 which permits the key 41 to reciprocate to a slight extent 'while swinging about the pivot and also prevents the member 46 from rotating upon its ownaxis. The key 41 prevents the flow of 40 refrigerant directly from the inlet 36 to the outlet' 50. The movement of the member 46 about its orbit in contact with the pum chamber wall through the pipe 54 to a cooling coil 55 whence it is forced through the pipe 56 into the cavity 51 in the shaft 40. The cavity 51 may be connected 55 The 15 by means of passages 58 with bearing surfaces such as occur between the off-set 45 and the pumping member 46 or between the end plates 5| or 11 and the shaft 48 of the pump. A passage 59 may be provided in the upper end plate 5| so that lubricant after having been forced into the cavity 51 is discharged through some of the passages 58 and the passage 59 back into the reservoir 32, to provide a constant circulation of the lubricant through the cooling coil 55. The lubricant in this circuit is thus maintained under high side refrigerant pressure throughout.

The pump 53 may be drivingly connected to the refrigerant pump. Thus the key 41 may form the reciprocating plunger of the pump 53. A

jacket 68 may be placed around the free end of the key 41. The jacket 68 thus forms a cavity 6|, which may be connected by the pipe 52 with the reservoir 32. A check valve 63 may be placed in the passage 52. The cavity 6| may also be connected to the pipe 54. An outwardly directed check valve 64 may be placed in the pipe 54. It will thus be seen that as the member 46 moves in a circular orbit because of the rotation of the shaft 48, that the key 41 is reciprocated. The reciprocation of the key 41 in the cavity 6| pumps the lubricant past the check valve 63 from the reservoir 32, then past the check valve 64 into the pipe 54, and thence to the lubricant cooling coil 55. From thence the lubricant passes through the pipe 56, cavity 51, passages 58 and passage 59 back into the reservoir 32. Thus a closed circuit is formed for the lubricant, said circuit including the bearings of the refrigerant pump, the

lubricant pump 53 and the reservoir 32.

The lubricant pump 53 has been shown in Fig.

3 as in a different horizontal plane from the re- The casing member 1| may be connected to the upper end plate 5| by means of bolts 13. The end plate 5| may include an upwardly directed dome member 14 to which the plate 44 may be secured by screws 15, thus forming the top of lubricant and refrigerant reservoir 32. .Passages 16 may join the 'ower portion of the reservoir 32 formed by the plate 1| with the upper portion of the reservoir 32 formed by the plate 5| and dome member 14.

The lower plate may be provided witha cylindrical extension 11 which forms the lower shaft bearing casing. A bearing member 18 may be placed in the extension 11. A thrust bearing 18 may be threadingly engaged with the interior of the extension 11 and the end of the casing may be sealed by plate 88 to which the lubricant pipe 56 may be connected.

A dome shaped casing 8| may be placed around the refrigerant liquefying unit. .The casing 8| nism in any suitable manner.

axially from the refrigerant liquefying unit. The casing 8| causes the air which is circulated by the fan to pass over the receiver 35, the condenser 33 and the lubricant cooling coil as well as other parts of the refrigerant liquefying unit. The air may pass out through an opening 85 to the top of the casing 8|. A combined stand and auxiliary casing 86 may be placed underneath the pumping mechanism. The stand 86 may be provided with downwardly directed legs 81 in order to provide air passages 88. The upper end of the stand 86 may include a perforated plate 89 provided with air openings 98, thus providing a continuous air passage from the air inlets 88 through the openings 98, up

through the casing 8| and out through the opening 85.

The stand 86 may support the pumping mecha Thus the plate 89 may be provided With upwardly extending cylindrical cups 9| adapted to .receive the lower ends of the rubber blocks 18. The condenser 33 and the receiver 35 may be placed under the plate 89 in the stand 86 and the connections to the pumping machinery may be made through openings provided in the plate 89.

The pipe 23 may be connected through a fitting 92 provided with a spring pressed check valve 93.

The reservoir 32 may be connected with the condenser 33 by means of a needle valve controlled fitting 94. The motor casing 95 may be provided with the necessary openings, one of which is shown at 96 for permitting a certain amount of air to circulate through the motor parts.

' The pumping mechanism may be slightly modified as shown in Figs. 6 to 9 inclusive. The shaft 48a may correspond with the shaft 48 in the mechanism heretofore described. The refrigerant may enter the pumping mechanism throughthe inlet 36a and may be discharged through the discharge opening 580. The vanes I88 may be keyed in an excentrically mounted rotary member |8|, with their outer. edges |82 bearing against the inner cylindrical surface |83 of the cylindrical pump casing |84. Springs I85 are placed in cavities Bla. which may also constitute the lubricant pumping chambers. Thus the cavities 6|a may be connected to the lubricant inlet pipes 52a in the end plates I86 and I81 and may also be connected to the lubricant outlet pipe 54a in the end plates I06 and I81. This may be accomplished by providing suitable semi-circular grooves H8 and H I which may be connected with the appropriate pipes 54a and 52a respectively. It will thus be seen that the vanes I88, while they are moving outwardly, suck the lubricant through the pipes 52a into the grooves and thence into the cavity 6|a. Upon the inward movement of the vanes .|88 the lubricant in the cavities 6|a. is forced into the grooves H8 and from thence into the pipes 54a. Thus, in' this embodiment, the rotary pumping member is also drivingly connected with a reciprocating lubricant pumping member. 4

The pump shown in Figs. 6 to 9 inclusive may be placed in a lubricantliquefying unit similar to that shown in Figs. 1 to 5. The'lubricant circulated by the lubricant pumps in this modification may be circulated through a cooling coil similar to coil 55, and the lubricant may be forced into bearings I89 through passages H2 and 3. In this embodiment, a resistance may be interposed between the oil discharge from the cooling coil 55 and the reservoir 32, and the passages H2 and 3 are in parallel with the 2,134,886 i ii flow of oil through the cooling coil. In this embodiment the oil reservoir 32 may be made by a casing separate from the pump chamber.-

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A motor-compressor unit comprising a casing in which a compressor is sealed in fluidtightrelationship, a motor stator supported exteriorly of and connected to said casing, a drive shaft passing through a. stuffing box in said casing, said shaft having a driving connection with said compressor in said casing and supporting a motor rotor exteriorly of said casing in operative relationship to said stator, lubricated bearing means for supporting said shaft and extending a sufiicient longitudinal contact along said shaft and being of a nature to align said shaft, means positively circulating lubricant to said lubricated bearing means, the entire lubricated bearing means being within said sealed casing and forming the sole bearing support for said shaft.

2. A'motor-compressor unit comprising a casing in which a compressor is'sealed in fluid-tight relationship, a motor stator supported exteriorly of and connected to said casing, a drive shaft passing through a stuffing box in said casing, said shaft having a driving connection with said compressor in said casing and supporting a motor rotor exteriorly of said casing in operative relationship to said stator, lubricated bearing means for supporting said shaft and extending a sumcient longitudinal contact along said shaft and being of a nature to align said shaft, means positively circulating lubricant to said lubricated bearing means, the entire lubricated bearing means being Within said sealed casing and forming the sole bearing support for said shaft and a fan driven from said shaft.

3. A motor-compressor unit comprising 9. casing in which a compressor is sealed in fluid-tight relationship, a lubricant sump in said casing, a motor stator supported exteriorly of and connected to said casing, a drive shaft passing through a stuffing box in said casing, said shaft having a driving connection with said compressor in said casing and supporting a motor rotor exteriorly of said casing in operative relationship to said stator, lubricated bearing means for supporting said shaft and extending a sumcient longitudinal contact along said shaft and being of a nature to align said shaft, means positively circulating lubricant to said lubricated bearing means, the entire lubricated bearing means being within said sealed casing and forming the sole a one piece cylinder block projecting into said recess and positioned thereby and forming 2. cylindrical chamber concentric with said shaft in radial alignment with said eccentric, end means closing said cylindrical chamber, an impeller mounted on said eccentric and operating in said cylindrical chamber, inlet and outlet ports for said chamber, a divider block between said ports,

having an annular recess at one side, a shaft seal cavity within said frame at the opposite side, a shaft journaled in said frame member,-shaft seal means within said cavity and carried by said frame member through which said shaft passes, rotary compressor mechanism carried by said frame member and driven by said shaft, said compressor mechanism including a one-piece cylinder member having a portion projecting into said recess and positioned thereby, means surrounding said cylinder member cooperating with said frame member forming a'high pressure re- I frigerant andilubricant chamber, an oil pump driven by said shaft for circulating lubricant to the shaft seal cavity and to the bearing surface between said shaft and said frame, and a passage in said frame member for returning ex-- cess lubricant from said bearing surface to said chamber, the outlet of said discharge passage being disposed above said bearing surfaces and above the lubricant level in said chamber whereby an adequate supply of lubricant'is provided for the entire bearing surface between said shaft and said frame.

6. In combination, a substantially circular compressor frame, a shaft journaled directly in said frame and having ends projecting beyond both sides of said frame, said frame having an' integral portion forming an enlarged chamber adjacent one end of said shaft, a running seal for said shaft within said chamber, an eccentric'on said shaft, said frame having an annular recess remote from said running seal, a block having a cylin'drical chamber concentric with said shaft, said block having a portion fitting within said recess and positioned thereby, means carried by said frame member for completing said cylindrical chamber, means cooperating with said frame member forming a lubricant reservoir in which said block'is at least partially submerged,

an impeller-mounted on said eccentric and 0pcrating in said cylindrical chamber, inlet and outlet ports for said cylinder, a. divider block between said ports, and means for pumping lubricant from said reservoir to said shaft seal, said frame member having a lubricant passage joining said reservoir and said chamber facilitating the housing and circulation of lubricant.

ROBERT-M. GETCHELL. RALPH K. MILLER. 

